1. Field of the Invention
This invention relates to steer axles and, in particular, to a mechanism for retaining the kingpin within a kingpin bore of the steer axle.
2. Disclosure of the Related Art
A conventional steer axle assembly includes a steer axle beam that defines a kingpin bore at either longitudinal end. A kingpin is received within each kingpin bore and supports a conventional steering knuckle which in turn supports a steerable wheel. Conventional kingpins, as illustrated in U.S. Pat. No. 5,709,399 issued to Smith, are secured against rotation within the kingpin bore using one or move draw keys that are inserted through bores drilled through the axle beam.
The use of draw keys to prevent movement of kingpins in steer axles has several drawbacks. First, the use of draw keys requires relatively expensive machining (off-axis drilling and tapping) and manual handling of the steer axle beam. Second, draw keys are a source of contamination in the normal vehicle environment. Finally, draw keys become corroded relatively quickly and are therefore difficult to disassemble in the filed and are subject to failure. Some steer axles have overcome one or more of these drawbacks by incorporating tapered or interference type kingpins rather than drawn keys. Tapered and interference type kingpins are difficult to service in the field, however.
The inventors herein have recognized that there is a need for a steer axle kingpin assembly that will minimize or eliminate one or more of the above-mentioned deficiencies.
The present invention provides a steer axle kingpin assembly for retaining the kingpin within a kingpin bore of the steer axle.
A steer axle kingpin assembly in accordance with the present invention includes a body portion configured to be received within a kingpin bore of a steer axle. The body portion is disposed about a longitudinal axis and has a first axial bore and a first radial bore in communication with the first axial bore. The assembly also includes a first bearing member disposed within the first radial bore. The bearing member may comprise a ball bearing. The assembly finally includes a first lock pin disposed with the first axial bore that urges the first bearing member radially outwardly and into engagement with a surface of the kingpin bore.
A steer axle kingpin assembly in accordance with the present invention represents a significant improvement as compared to conventional kingpin assemblies. In particular, the inventive steer axle kingpin assembly reduces the overall cost of the steer axle by eliminating expensive machining of the steer axle beam and enabling automated manufacture of the steer axle beam. A steer axle incorporating the inventive: kingpin assembly is also subject to less contamination than conventional steer axles. Finally, the inventive kingpin, assembly is easier to repair in the field than conventional kingpin assemblies.